Eur. Phys. J. A (2007) 33: 107-117
https://doi.org/10.1140/epja/i2007-10417-3

Regular Article - Hadron Physics

¯N interaction from meson-exchange and quark-gluon dynamics

¹ Institut für Kernphysik, Forschungszentrum Jülich, D-52425, Jülich, Germany
² Instituto de Fısica Teórica, Universidade Estadual Paulista, Rua Pamplona, 145, 01405-900, São Paulo, SP, Brazil
³ Helmholtz-Institut für Strahlen- und Kernphysik (Theorie), Universität Bonn, Nußallee 14-16, D-53115, Bonn, Germany

^* e-mail: j.haidenbauer@fz-juelich.de

Received: 27 April 2007
Accepted: 27 June 2007
Published online: 27 July 2007

Abstract

We investigate the ¯N interaction at low energies using a meson exchange model supplemented with a short-distance contribution from one-gluon exchange. The model is developed in close analogy to the meson-exchange KN interaction of the Jülich group utilizing SU(4) symmetry constraints. The main ingredients of the interaction are provided by vector meson (ρ , ω exchange and higher-order box diagrams involving ¯^* N , ¯Δ , and ¯^*Δ intermediate states. The short-range part is assumed to receive additional contributions from genuine quark-gluon processes. The predicted cross-sections for ¯N for excess energies up to 150MeV are of the same order of magnitude as those for KN but with average values of around 20mb, roughly a factor two larger than for the latter system. It is found that the ω -exchange plays a very important role. Its interference pattern with the ρ -exchange, which is basically fixed by the assumed SU(4) symmetry, clearly determines the qualitative features of the ¯N interaction --very similiar to what happens also for the KN system.